A new study has found that a diagnosis of depression in adulthood could more than double the risk of developing dementia in old age.
The research, published on Monday in the academic journal JAMA Neurology, utilized data from over 1.4 million Danish citizens who were followed from 1977 to 2018, said the lead author of the study, Dr. Holly Elser, an epidemiologist and resident neurologist at the University of Pennsylvania.
Nearly 1 in 5 American adults were diagnosed with depression, and the prevalence varies significantly by state, according to the CDC.
The study identified individuals with and without a diagnosis of depression and followed them over the years to see who developed dementia later on. The researchers took into account factors such as education, income, cardiovascular diseases, diabetes, substance use disorders, and bipolar disorder.
The extensive dataset and numerous analyses conducted by the researchers made their conclusions robust and reliable, but the study is limited by the lack of availability of information such as genetic data, noted Dr. Natalie Marchant, an associate professor in the Division of Psychiatry at University College London. Marchant was not involved in the research.
Late-life depression is often thought of as an early symptom of dementia, and many previous studies have linked them, said Elser. However, the latest study shows a connection between the risk of dementia and depression diagnoses even in early and mid-life.
“Therefore, our findings provide robust evidence that depression is not only an early symptom of dementia but also increases the risk of developing it,”Dr. Natalie Marchant
Although the association between depression and dementia has proven to be strong, the study still does not answer some questions.
“For example, there may be shared common risk factors for depression and dementia that occur earlier in life, depression may increase the risk of dementia through alterations in key neurotransmitter levels, or depression may lead to changes in health behaviors that, in turn, increase the risk of dementia,” she added in an email.
“There is a clear need for future research to examine the potential mechanisms linking early-life depression to the later onset of dementia,” Elser affirmed.
Another aspect of the results that could be further explored is the closer relationship found in men than in women, according to Marchant.
“It’s an interesting finding, which I hope will continue to be studied,” she added in an email. “It supports the idea that we should routinely consider dementia risk factors in men and women separately because there may be different mechanisms involved.”
Why receive treatment for depression The double blow of depression and dementia can be frightening, and you may wonder: Will receiving treatment reduce my risk?
It’s still unclear.
According to Elser, the latest study examined antidepressant treatment in the six months following diagnosis and did not observe differences in risk between treated and untreated groups.
It will be important to continue researching whether medication and cognitive-behavioral therapy at different times and with different durations are effective in reducing risk, she added.
Preliminary results from other observational studies show that older adults who participated in therapy that reduced their symptoms of depression and/or anxiety also had a lower risk of future dementia, Marchant added.
However, since the studies were observational, researchers cannot claim whether therapy led to fewer cases of dementia, she added.
“Nevertheless, taking care of mental health remains important for well-being in the present,” said Marchant. Regardless of the risk of dementia, treating depression should be a priority, Elser agreed.
“Given that depression is extremely common and is associated with significant individual and social costs, effective treatment of depressive symptoms should be a priority, regardless of whether they confer a risk of dementia later in life,” she stated.
Original source: This information was Initially covered by Cnnespanol.cnn.com and has been translated for our readers.